Many wheel assemblies for skateboards, rollers skates, longboards, scooters, etc., have beginnings in a skate wheel design described in the U.S. Pat. No. 37,305, to Plimpton, issued Jan. 6, 1863 (hereinafter “Plimpton”). The small, wooden wheels of Plimpton have wide flat bottoms due to a tendency of the wooden wheels to slip on the smooth wooden floor of a roller rink. Skate wheels were later improved by an addition of bearing assemblies as described in U.S. Pat. No. 308,990, to Richardson, issued Dec. 9, 1884. Skate wheels were further improved in an effort to replace the wooden tire with a rubber tire, as described in U.S. Pat. No. 2,669,485, to Newman, issued Feb. 16, 1954. Beginning in the 1960's, skate wheels began to be increasingly used on roads because of the emergence of outdoor skates and the introduction of the skateboard. An example of a wheel for a skateboard for outdoor use is described in U.S. Pat. No. 4,114,952 to Kimmel, issued Sep. 19, 1978.
Wheel assemblies were later improved as an inline roller skate, as described in U.S. Pat. No. 4,492,385, to Olson et al., issued Jan. 8, 1985. Subsequent success of the inline skate underscored disadvantages inherent in using a wide and flat tire on a less than smooth surface. For example, the disadvantages include increased rolling resistance. Furthermore, wide and flat tires experience additional resistance during turns since an outer portion of the tire is being pushed to rotate faster than an inner portion of the tire. As a result, the tires wear unevenly, which decreases a lifetime of the tire and can lead to rougher (e.g., bumpier) rides on the skateboard or roller skate. Moreover, wide and flat tires are more likely to be slowed or stopped by obstacles (e.g., rocks, pebbles, cracks, road debris, etc.) during use because the width of the wide and flat tires inhibits the obstacles from being pushed to a side of the tire. Additionally, the wide and flat tires require a significant amount of material, and therefore cost, to manufacture. Likewise, wide and flat surfaces of the wide and flat tire are less than ideal for gripping wet surfaces, and even when grooves are cut into the wide and flat tire to enhance grip (e.g., traction), the grooves quickly fill with dirt, tar, and other road debris, rendering the grooves ineffective.
Other improvements to skate wheels include steering mechanisms as described in U.S. Pat. No. 5,330,214, to Brooks et al., issued Jul. 19, 1994, and large troughs in centers of the skate wheels as described in U.S. Pat. No. 7,311,318, to Funk, issued Dec. 25, 2007.